The present invention relates to a low profile tire for an SUV (sport utility vehicle). Specifically, the present invention relates to a pneumatic tire capable of having its enhanced rut performance with its dry and wet performances being reconciled with each other.
An example of a pneumatic tire for an SUV is a pneumatic tire with a nominal width of not less than 255 mm, an outside diameter of not less than 720 mm and an aspect ratio of not more than 55%. The pneumatic tire has a designated direction of sides thereof for mounting the tire on a vehicle. A general design of the pneumatic tire of this kind is its tread section including four main grooves extending in the tire's circumferential direction with five land portions being defined by these four main grooves (see Patent Documents 1 and 2, for example).
Nevertheless, the low profile tire with such a large nominal width and outside diameter generates a large camber thrust, and accordingly has a disadvantage that its driving performance (hereinafter referred to as “rut performance”) is bad in road surfaces affected by wheel ruts. With this taken into consideration, increase in a groove component of the tire's tread section makes it possible to improve the tire's rut performance and additionally enhance its wet performance. In the case where the groove component is increased in the tread section, however, this increase reduces the dry performance of the tire. As a result, it is difficult to satisfy the dry performance, the wet performance and the rut performance simultaneously.    Patent Document 1: Japanese patent application Kokai publication No. 2005-53311    Patent Document 2: Japanese patent application Kokai publication No. 2006-143040